N

Grinding time (t)

The average particle size ( ${\overline{x}}_{50}$ )

Particle size distribution

Specific surface area (m²/cm³)

1

0 (unmilled)

4.6 µm

133 nm ÷ 7.7 µm

1.30

2

15 min

429 nm

319 nm ÷ 6.5 µm

14.06

3

30 min

381 nm

296 nm ÷ 530 nm

15.80

4

1 h

470 nm

368 nm ÷ 659 nm

12.81

5

3 h

280 nm

238 nm ÷ 368 nm

21.49

6

5 h

406 nm

319 nm ÷ 570 nm

14.84

7

6 h

221 nm

41 nm ÷ 343 nm

27.35